Maine is known as the Pine Tree State, honoring the millions of acres of woodlands. Portland became known as "Forest City" because of the large shade trees throughout the city. But it was far from the only community in the state with shade trees lining most streets.

American elms, once the most common tree to line city streets, began to succumb to disease in the 1930s, leaving holes in the landscape of many cities. Sometimes trees also are threatened by fire or natural disasters.

Trees can help improve the quality of life, providing shade, cleaner air, beauty, and recreational opportunities.

Trees also have important economic functions, especially in forested states like Maine. Trees are used for extracting maple sap to process into syrup, for firewood, for lumber, and for pulp for the paper industry. And some trees are so significant or beautiful, they are given special names.